Purification of human diploid fibroblast interferon by immobilized neuraminidase.

An efficient method for the purification of human fibroblast interferon (IF) based on binding via the N-acetyl neuraminic acid (N-ANA) residue of the IF molecules to the immobilized neuraminidase has been developed. Binding of IF occurred at pH 4.5 and elution of the bound activity was effected at pH 9.5. Specific activity of IF in the alkaline eluate was increased by a factor in excess of 200 and the IF thus recovered had probably retained most of the N-ANA moieties.